Background: Dengue fever will present with varied manifestations in children. Cardiac manifestation in Dengue fever are rare but not unknown. Hence this study was undertaken to evaluate Cardiac Manifestations in children with dengue fever. Materials And Methods: This is a prospective study done at Department of Paediatrics, at N.M.C.H. Jamuhar Sasaram, Rohtas. Inclusion Criteria Children <12 years, admitted to Department of Paediatrics , who are confirmed (positive Non Structural 1 Antigen or IgM ELISA) cases of dengue fever. Exclusion Criteria: Children with congenital /acquired heart disease. Conclusion: Cardiac manifestations in children with Dengue are not uncommon regardless of clinical type of Dengue, though most of the cardiac involvement in children with Dengue are subclinical. ECG changes noticed in 13(33%) of cases. Sinus tachycardia, bradycardia, ST- T changes, reduction ofejection fraction were common in Dengue With or Without Warning Signs.